placenta

a vascular organ, developed within the uterus of most mammals during gestation from the chorion of the embryo and a part of the maternal uterine wall, that is connected to the embryo by the umbilical cord and that is discharged shortly after birth: it serves as the structure through which nourishment for the fetus is received from, and wastes of the fetus are eliminated into, the circulatory system of the mother

placenta

noun

pl.pla·cen·tas or pla·cen·tae

a. A membranous vascular organ that develops in female eutherian mammals during pregnancy, lining the uterine wall and partially enveloping the fetus, to which it is attached by the umbilical cord. Following birth, the placenta is expelled.

b. A similar organ in marsupial mammals, consisting of a yolk sac attached to the uterine wall.

c. An organ with similar functions in some nonmammalian animals, such as certain sharks and reptiles.

Botany The part within the ovary of a flowering plant to which the ovules are attached.

Origin of placenta

New Latin, from Latin, flat cake, alteration of Greek plakoenta, from accusative of plakoeis, flat, from plax, plak-, flat land, surface; see plāk-1 in Indo-European roots.

Related Forms:

pla·cen′tal

adjective

placenta

Noun

(plural placentae or placentas)

(anatomy) A vascular organ in mammals, except monotremes and marsupials, present only in the female during gestation. It supplies food and oxygen from the mother to the foetus, and passes back waste. It is implanted in the wall of the uterus and links to the foetus through the umbilical cord. It is expelled after birth.

(botany) In flowering plants, the part of the ovary where ovules develop; in non-flowering plants where the spores develop.

Origin

From Medieval Latin placenta uterina (“uterine cake"), from Latinplacenta (“flat cake"), because of the flat round shape of the afterbirth.